Group III nitride semiconductor stacked structure

Abstract

An object of the present invention is to provide a Group III nitride semiconductor stacked structure with a low dislocation density obtained by stacking only a semiconductor layer on a flat substrate by the use of a normal epitaxial growth method without processing the substrate or a deposit layer on the substrate, wherein the dislocation density is 1×107 cm−2 or less. The inventive Group III nitride semiconductor stacked structure comprises a substrate having a surface roughness (Ra) of 1 nm or less and a Group III nitride semiconductor layer directly stacked on the substrate, wherein the Group III nitride semiconductor layer comprises a plurality of layers put into contact with each other, the plurality of layers comprise a high-concentration impurity atom layer and a low-concentration impurity atom layer, and the high-concentration impurity atom layer is present on the substrate side.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is an application filed under 35 U.S.C. §111(a) and claiming benefit, pursuant to 35 U.S.C. §119(e)(1), of the filing date of the Provisional Application No. 60 / 679,978 filed on May 12, 2005, pursuant to 35 U.S.C. §111(b).TECHNICAL FIELD [0002] The present invention relates to a Group III nitride semiconductor stacked structure, and a Group III nitride semiconductor light-emitting device using the same. BACKGROUND ART [0003] A Group III nitride semiconductor formed on a substrate has been heretofore used as a functional material for fabricating a Group III nitride semiconductor light-emitting device with a pn-junction type structure capable of emitting visible light at a short wavelength, such as a light-emitting diode (LED) and a laser diode (LD) (see, for example, Japanese Unexamined Patent Publication (Kokai) No. 2000-332364). For example, at the fabrication of an LED emitting near ultraviolet light, blue light or gre...

AI Technical Summary

Benefits of technology

[0011] An object of the present invention is to provide a Group III nitride semiconductor layer with a low dislocation density obtained by stacking only a semiconductor layer on a flat substrate by the use of a normal epitaxial growth method without processing the substrate or a deposit layer on the substrate, wherein the dislocation density is 1×107 cm−2 or less. Another object of the present invention is to provide a Group III nitride semiconductor light-emitting device and a lamp, each using the above-described Group III nitride semiconductor layer and ensuring excellent light emission efficiency.

[0028] In the stacked structure for a Group. III nitride semiconductor device of the present invention, the dislocation density of the Group III nitride semiconductor layer is very small and 1×107 cm−2 or less. Accordingly, a Group III nitride semiconductor light-emitting device with excellent light emission efficiency can be produced by using this stacked structure. That is, in the case of a current injection-type light-emitting device, the crystal defect which traps a carrier and is a non-light-emitting center can be reduced and this is expected to yield an enhancement of light emission efficiency, an enhancement of the peak inverse voltage and an enhancement of electrostatic breakdown voltage for an LED device. Also, in a laser device, the threshold current can be reduced.

[0029] Furthermore, this stacked structure is obtained by stacking only a semiconductor layer on a flat substrate by the use of a normal epitaxial growth method without processing the substrate or a deposit layer on the substrate and, therefore, the production cost is very low.

Problems solved by technology

However, in such a method, as the substrate or a deposit layer on the substrate is processed, the formation of an insulating film or a patterning process such as photolithography and etching is complicated and the finally formed film allows for the presence of a dislocation distribution corresponding to the film shape.

However, even in such a method, the process is cumbersome because the substrate, on which a film is grown, is once taken out from the growth furnace and, after applying a processing for the pit formation in the grown film, a layer capable of exerting a device function, such as light-emitting layer, is again grown.

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